#include <stdio.h>
int missingNumber(int* nums, int numsSize) {
    int sum = (numsSize * (numsSize + 1)) / 2;
    for (int i=0; i < numsSize; i++)
    {
        sum -= nums[i];
    }
    return sum;
}
int main()
{
    int nums[] = { 1,2,4,3,5,7,5,5,6 };
    int numSize = 10;
    missingNumber(&nums,numSize);
}